Does WD-40 remove car scratches? Plus nine other things we learned testing car scratch removers

We've tested car scratch removers from popular brands to see which are best at covering up scuffs and scrapes.

We also tested WD-40 to see if it can hide scratches – as the manufacturer and countless You Tubers claim.

Here are 10 things to remember next time you tackle a troublesome car scratch.

1. WD-40 does work... sort of

WD-40 stops squeaks, loosens rusted parts, frees sticky mechanisms – and also hides shallow scratches.

However, we found that it takes four applications to make a noticeable difference, and it will wash away the next time you clean the car.

In other words, WD-40 is a temporary fix until you have time to get one of the best car scratch removers we discovered through our testing.

2. Most scratch removers only remove shallow scratches

There are three types of scratches that can affect a car panel:

• Shallow scratch: a scratch to the clear coat
• Medium scratch: a scratch through the clear coat and into the base coat
• Deep scratch: a scratch into the primer or the metal of the car panel.

Most car scratch removers are designed to take care of shallow scratches, scuffs and swirl marks.

Some of the products we tested faded the appearance of medium scratches, but none worked on deep scratches. However, keep in mind that they don't claim to work on anything more than a shallow scratch. 

If you spot a scratch on your car, but can't tell how deep it is by sight, pass your fingernail over the mark. If your fingernail gets caught, this is a medium scratch at least. With deep scratches, you'll see the primer or metal itself showing through.

If you identify a deep scratch on your car, it may be time to turn to a professional. Depending on the level of damage, a bodywork repair shop will either be able to smooth it out or, if need be, replace the car panel.

Find a mechanic you can trust on Which? Trusted Traders.

3. You don't always need to pay more

We tested a range of car scratch removers priced between £4 (Car Pride's scratch remover pen) and £32 (Angelwax's Enigma AiO).

While some pricier options did well in our tests, we found you don't have to shell out a lot for a repair job you'll be happy with. We found an inexpensive car scratch remover that did an excellent job, so we've named it both a Best Buy and Great Value option. 

4. Some repairs don't last long

We investigated whether the car scratch removers we tested would survive a hand wash after their application.

We applied the products, let them dry and then washed the panel five times with car shampoo.

For the majority of the products we tested, the scratches reappeared before the five washes were up:

• The WD-40 washed away with the first treatment
• The repairs from three car scratch removers only survived one wash
• Another three car scratch removers only survived two washes
• Repairs from one scratch remover survived four washes
• The repairs from the best product survived all five washes

5. Washing creates a better finish

Once you've used a car scratch remover that gives you good results, you may nonetheless be dismayed to find the area of bodywork you've worked on left with a bit of a haze.

This duller finish is nothing to worry about. Give your car a once-over with a good polish, and you'll be that much happier with the end results.

6. You shouldn't need extra tools 

Some car scratch removers can be used with an electric car polisher on deeper scratches. 

We tested the Halfords 110W Polisher on medium and deep scratches with three compatible car scratch removers. 

We found that using a polisher didn't do a significantly better job at removing these types of scratches compared to applying the products by hand with a microfibre cloth. 

If you have scratches that get into your paintwork, we'd recommend taking your car to a garage for a better result.

7. Preparation is key

One thing we can't recommend highly enough is prepping the area you're going to work on with the car scratch removers.

By prepping, we mean washing the vehicle with car shampoo to make sure there's no lurking grit. If this isn't done, there is a risk that rubbing a foam pad or microfibre cloth over the area, with grit or sand on it, could make the scratches worse.

Out of car shampoo? We pitted shampoos and waxes against all-in-one products to find the best car wash kit.

8. Avoid using it on a sunny day

Not all car scratch removers do well when applied in direct sunlight. If this is the case, they do say so in their instructions.

9. Take your time

We found that many car scratch removers need more than one application to get rid of a shallow scratch.

10. Do a test run

Many of the scratch removers we tested suggest applying the product to a small out-of-the-way area first. This is to make sure it reacts well with your paint job.

It will say in the instructions if you need to do this.